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Car decelerates...

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  Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 19:42 -0800
    Re: Car decelerates... Melzzzzz <mel@zzzzz.com> - 2016-01-28 04:44 +0100
      Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 19:48 -0800
        Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 15:28 +1100
          Re: Car decelerates... mlwozniak@wp.pl - 2016-01-27 22:58 -0800
            Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 19:57 +1100
              Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 01:07 -0800
                Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 22:08 +1100
                  Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 03:51 -0800
                    Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-29 10:53 +1100
                      Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 19:31 -0800
                        Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 06:40 +0100
                          Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 22:29 -0800
                          Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 22:57 -0800
                            Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:08 +0100
                              Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:18 -0800
                                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:24 +0100
                                Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:25 -0800
                                  Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-29 10:19 -0800
                                    Re: Car decelerates... Odd Bodkin <bodkinodd@gmail.com> - 2016-01-29 13:30 -0600
                                    Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 12:21 -0800
                                    Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 10:48 +0100
                                    Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-31 13:55 +0100
                                      Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-31 13:16 -0800
                              Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 00:35 -0800
                              Re: Car decelerates... Polikwaptiwa <polikw@polikwamail.org> - 2016-01-30 16:32 +0000
                                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-30 18:02 -0800
                            Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:19 +0100
                              Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:23 -0800
                                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:28 +0100
                                  Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:39 -0800
                                    Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 09:56 +0100
                                      Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 10:09 +0100
                                        Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 11:34 +0100
                            Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:20 -0800
                        Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-29 23:12 +1100
                          Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-29 12:33 +0000
                            Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-30 22:16 +1100
                              Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 12:25 +0100
                                Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-30 22:34 +1100
                                  Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 13:45 +0100
                          Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 04:42 -0800
                        Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:17 -0800
                          Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 06:23 -0800
                      Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-29 06:17 +0100
        Re: Car decelerates... Melzzzzz <mel@zzzzz.com> - 2016-01-28 13:37 +0100
        Re: Car decelerates... moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-01-28 19:33 +0000
    Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:08 -0800
      Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 20:28 -0800
        Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 20:34 -0800
          Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:50 -0800
          Re: Car decelerates... mlwozniak@wp.pl - 2016-01-27 23:00 -0800
            Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 23:34 -0800
              Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-28 07:23 -0800
              Re: Car decelerates... Odd Bodkin <bodkinodd@gmail.com> - 2016-01-28 09:59 -0600
                Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 22:27 -0800
              Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-28 16:49 +0000
              Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 22:29 +0100
        Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:53 -0800
        Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 07:47 +0100
          Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-28 18:22 +0000
            Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 22:31 +0100
    Re: Car decelerates... Koobee Wublee <koobee.wublee@gmail.com> - 2016-01-27 23:59 -0800
      Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 00:19 -0800
    Re: Car decelerates... jamesl51165@gmail.com - 2016-01-28 08:18 -0800
    Re: Car decelerates... Mike Fontenot <mlfasf@comcast.net> - 2016-01-28 09:46 -0700

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#375218

Użytkownik "Sylvia Else"  napisał w wiadomości grup 
dyskusyjnych:dh3leoF9k67U1@mid.individual.net...

On 30/01/2016 10:25 PM, Maciej Woźniak wrote:
>
>
> Użytkownik "Sylvia Else"  napisał w wiadomości grup
> dyskusyjnych:dh3kclF9bjuU1@mid.individual.net...
>
> On 29/01/2016 11:33 PM, Juan Sebastián wrote:
>> Sylvia Else wrote:
>>
>>> But you're asking whether it's curved as a consequence of the
>>> acceleration? No. Sylvia.
>>
>> In which case you must be able to point out the difference. You can't,
>> woman.
>>
>
> |I'm pretty sure
>
> Your Great Guru was pretty sure too, and he stated differently.
>

|People who don't understand the physics are only too able to misconstrue
|things that are said about it.

You're a perfect example.
But don't worry. You're in a good company. Whoever was the third
person understanding relativity, he died a long time ago, samely
as the two others. 

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#375136

W dniu piątek, 29 stycznia 2016 13:12:48 UTC+1 użytkownik Sylvia Else napisał:
> On 29/01/2016 2:31 PM, Jon Price wrote:
> > Ok,from cars (noninertial) reference frame which person in car considers to be at rest, persons body moves toward windshield. Person considers this due to a gravitational field.
> >
> > Is space-time curved here?
> >
> 
> Probably - it's rare to find cars far from the Earth, the mass of which 
> curves space somewhat.
> 
> But you're asking whether it's curved as a consequence of the acceleration?
> 
> No.

Your guru's answer was opposite.

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#375145

On Thursday, January 28, 2016 at 10:31:07 PM UTC-5, Jon Price wrote:
> Ok,from cars (noninertial) reference frame which person in car considers 
> to be at rest, persons body moves toward windshield. 
> Person considers this due to a gravitational field.

He can call it what he wants. It wont change the fact that his position as a function of time in the car's frame is ~ at²

> Is space-time curved here?

No, spacetime doesnt curve. What the inhabitants of the car can conclude is that their position as a function of time in the car's frame is ~ at². Now, *some* inhabitants of the car may call at² a "parabola" or a "curve". 

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#375147

W dniu piątek, 29 stycznia 2016 15:17:08 UTC+1 użytkownik rotchm napisał:
> On Thursday, January 28, 2016 at 10:31:07 PM UTC-5, Jon Price wrote:
> > Ok,from cars (noninertial) reference frame which person in car considers 
> > to be at rest, persons body moves toward windshield. 
> > Person considers this due to a gravitational field.
> 
> He can call it what he wants. It wont change the fact that his position as a function of time in the car's frame is ~ at²
> 
> > Is space-time curved here?
> 
> No, spacetime doesnt curve. 

Your insane guru stated oppositely.

>What the inhabitants of the car can conclude is that their position as a function of time in the car's frame is ~ at².

Well, for exactly the same reason your insane guru published his spacetime curvature mumble.

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#375103

Użytkownik "Sylvia Else"  napisał w wiadomości grup 
dyskusyjnych:dgvnvkFal3aU1@mid.individual.net...

On 28/01/2016 10:51 PM, mlwozniak@wp.pl wrote:
> W dniu czwartek, 28 stycznia 2016 12:08:35 UTC+1 użytkownik Sylvia Else 
> napisał:
>> On 28/01/2016 8:07 PM, mlwozniak@wp.pl wrote:
>>> W dniu czwartek, 28 stycznia 2016 09:57:51 UTC+1 użytkownik Sylvia Else 
>>> napisał:
>>>> On 28/01/2016 5:58 PM, mlwozniak@wp.pl wrote:
>>>>> W dniu czwartek, 28 stycznia 2016 05:28:08 UTC+1 użytkownik Sylvia 
>>>>> Else napisał:
>>>>>> On 28/01/2016 2:48 PM, Jon Price wrote:
>>>>>>> Ah, I wasn't clear. Consider cars reference frame to be at rest....
>>>>>>>
>>>>>>
>>>>>> The car's reference frame is accelerated.
>>>>>
>>>>> Tom would explain You, that if accelerated, there
>>>>> is no reference frame.
>>>>>
>>>>
>>>> It's not an inertial reference frame.
>>>
>>> Quoting Tom:
>>> This is wrong. In relativity and essentially all of modern physics there 
>>> is
>>> more: a frame of reference consists of a 3-D rectangular FRAME 
>>> (latticework) of
>>> rulers with a clock located at each junction; the clocks must all be 
>>> mutually
>>> synchronized. Constructing such a FRAME requires that the entire FRAME 
>>> be at
>>> rest in some inertial frame. It is NOT coincidence that the same word is 
>>> used.
>>> This _IS_ what "frame" means in modern physics.
>>> End of quoting.
>>>
>>> But, don't worry. Your relativity is obviously
>>> inconsistent, so You're free to write oppositely.
>>>
>>
>> I'm not sure what you're trying to prove here. The unadorned word
>> "frame" does mean inertial frame. One doesn't have to go around sticking
>> the word "inertial" in everywhere. But this is English, not math. One is
>> free to qualify the word "frame" with the word "accelerated", without
>> introducing any contradiction.
>
> Sylvia, You really don't have to convince me, that physicists
> are free to break the rules they invented and are demanding
> from others.
>

|No rules are being broken here.

:)


Sylvia. 

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#375032

On Wed, 27 Jan 2016 19:48:06 -0800 (PST)
Jon Price <jonelwoodprice@gmail.com> wrote:

> Ah, I wasn't clear. Consider cars reference frame to be at rest....
"
On the surface of the Earth, inertia is often masked by the effects of
friction and air resistance, both of which tend to decrease the speed
of moving objects (commonly to the point of rest), and gravity. This
misled the philosopher Aristotle, to believe that objects would move
only as long as force was applied to them:
"

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#375068

Jon Price <jonelwoodprice@gmail.com> writes:

>Ah, I wasn't clear. Consider cars reference frame to be at rest....

The car may be a reference frame, but it is not an INERTIAL reference
frame.  While velocity may be relative, acceleration is not.

Also consider the car bolted to the deck of a spinning merry-go-round.
Occupants will see other "strange" forces.  It's another non-inertial
reference frame.

Heck, just think of the car just sitting there on the road.  There's 
another strange force pulling everything down.  It's called gravity, and
the surface of the earth is non-inertial for that reason.

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#374996

On Wednesday, January 27, 2016 at 10:42:47 PM UTC-5, Jon Price wrote:
> Drivers body moves forward.
> 
> From cars reference frame, what causes forward body movement?
> 
> A gravitational field?

Nothing causes it, except for your declaration that the body inside moves forward. This is basically Einstein's elevator gedanken. If the body is projected in a direction, then you model the reference frame (the car's internal frame) as such (An appropriate metric/geometry). Call it "gravitational field" or what ever, but it wont change the fact the the body moved (accelerated) forward and wont change your chosen model.

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#374997

But body doesn't start moving for no reason, right?

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#375000

Sylvia, Cars reference frame can be considered to be at rest.
Also, thought that principle of relativity applied to both inertial and noninertial reference frames in general relativity.

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#375002

On Wednesday, January 27, 2016 at 11:35:04 PM UTC-5, Jon Price wrote:
> Sylvia, Cars reference frame can be considered to be at rest.

Its is at rest (wrt itself) but it is not an inertial frame. 

> Also, thought that principle of relativity applied to both 
> inertial and noninertial reference frames in general relativity.

And it does. It is that the expression (formulas) of the laws are written differently. In the non inertial frame, you need to specify its non inertial aspect (basically, specifying its metric). Once specified, then the body's position (movement) in the cars (non inertial) frame will be deduced.  But note that the specification of which metric you use is defined by your claim that the body moves forward in the cars frame; its redundant, a tautology. 

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#375018

W dniu czwartek, 28 stycznia 2016 05:35:04 UTC+1 użytkownik Jon Price napisał:

> Sylvia, Cars reference frame can be considered to be at rest.

And commmunism can be considered to be the best 
system under the Sun.
It's just that  considering it this way is very, very 
stupid.

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#375022

Well, Einstein considered it this way I believe. 

Scenario is like this...
Car is moving let's say w constant velocity with respect to road initially.
Then car decelerates. As we know (I think), drivers body moves forward.

Now, same scenario but consider cars reference frame to be at rest.
What "causes" drivers body to move forward?

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#375034

On Thursday, January 28, 2016 at 2:34:08 AM UTC-5, Jon Price wrote:
> Well, Einstein considered it this way I believe. 
> 
> Scenario is like this...
> Car is moving let's say w constant velocity with respect to road initially.
> Then car decelerates. As we know (I think), drivers body moves forward.

Well, no, the body doesnt "move forward". Take great care in your descriptions else you will get confused as you are now. Viewed from the ground "inertial" frame, the body continues forward at constant speed and the car is slowing down as posited. Therefore, the closing speed of the car and body changes; the body is approaching the windshield (faster & faster). The "cause" of this effect is that YOU posited that the car decelerates wrt the ground. 

> Now, same scenario but consider cars reference frame to be at rest.
> What "causes" drivers body to move forward?

Again, as I told you, imagine the driver in en enclosed car (he cant see outside and doesnt control the car) and all the sudden is is "thrown forward". The cause is that YOU posited it that way. If the inhabitants of the car want to describe their enclosed space, they will use a model where bodies will "accelerate" towards the windshield (a model like gravity/GR). If you were a roadside observer, you would describe the scenario as done in the previous paragraph; you could also translate your inertial model to the drivers non inertial frame and hence deduce the exact same model as found by the car's inhabitants. 

IOW, you use a general model that can describe the effect from one frame to another; change of frames; map; etc... get the idea? 

There are no "causes" except for you *positing* the effect. Once posited, the general model (say, GR) gives you the eqs of motion depending on your choice of frame. 

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#375037

On 1/28/2016 1:34 AM, Jon Price wrote:
> Well, Einstein considered it this way I believe.
>
> Scenario is like this...
> Car is moving let's say w constant velocity with respect to road initially.
> Then car decelerates. As we know (I think), drivers body moves forward.
>
> Now, same scenario but consider cars reference frame to be at rest.
> What "causes" drivers body to move forward?
>

The frame of reference where the car is at rest is not an inertial 
reference frame. Since the car is decelerating and not in uniform 
motion, the frame that moves along with it is not in uniform motion 
either. This reference frame is thus a non-inertial reference frame. In 
non-inertial reference frame, mysterious "forces" without causes can 
appear. More accurately, in an non-inertial reference frame, the 
Newtonian laws of physics that you have ingrained in your head don't 
work any more. For example, those laws of physics say that something 
doesn't accelerate unless there is a net force acting on it; that 
something with no net force acting on it won't accelerate; and that an 
object's acceleration is proportional to the net applied force. So if 
you see the body move forward in this frame, the TEMPTATION is to apply 
Newton's laws and say, "Well, there must have been some force that 
caused that change in motion." But the thing is, Newton's laws don't 
apply well in this frame, and so your inference is mistaken. There is in 
fact no force that causes the body to move forward.

As you know, what's really going on here is that the seat applies a 
force to your legs (friction) to get your legs to slow down with the 
car. But you have a pivot at your hips and there is no force between 
your seat and your upper body that could decelerate your upper body, and 
so your upper body does not decelerate the way your legs do.

-- 
Odd Bodkin --- maker of fine toys, tools, tables

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#375110

W dniu czwartek, 28 stycznia 2016 16:59:07 UTC+1 użytkownik Odd Bodkin napisał:

> The frame of reference where the car is at rest is not an inertial 
> reference frame. 

Your fellow idiot Tom would explain you, that
if not inertial then it is not a frame of reference.

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#375043

Jon Price wrote:
> Well, Einstein considered it this way I believe.
> Scenario is like this...
> Car is moving let's say w constant velocity with respect to road
> initially.
> Then car decelerates. As we know (I think), drivers body moves forward.
> Now, same scenario but consider cars reference frame to be at rest. What
> "causes" drivers body to move forward?

Are you sure you want to know? In that case the car is accelerating
backwards in an attempt to catch up with the road moving, previously at
constant speed. In short, the car attempts to catch up with that speed.

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#375077

Dne 28/01/2016 v 08:34 Jon Price napsal(a):
> Well, Einstein considered it this way I believe. 
> 
> Scenario is like this...
> Car is moving let's say w constant velocity with respect to road initially.
> Then car decelerates. As we know (I think), drivers body moves forward.
> 
> Now, same scenario but consider cars reference frame to be at rest.
> What "causes" drivers body to move forward?
> 
The fictitious force
within accelerating non-inertial frame of reference.

Similarly as it is fictitious Coriolis force
causing hurricanes in Mexican gulf to rotate counter-clockwise.

-- 
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

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#375003

On Wednesday, January 27, 2016 at 11:28:13 PM UTC-5, Jon Price wrote:
> But body doesn't start moving for no reason, right?

It moves because you declared as so!
Imagine that you are in an enclosed box and all the sudden, you move forward. Then the conclusion is...that you moved forward! You can now model that any way you want (say, like x = at²)and say that the cause is this or that, but it wont change the fact that you moved forward and that your movement was found to be at². One might say that the equation at² is the cause (this is what is declared in popular descriptions of general relativity; the case is the curvature is space).

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#375013

Dne 28/01/2016 v 05:28 Jon Price napsal(a):
> But body doesn't start moving for no reason, right?
> 
The car reference frame
starts to be accelerating for a reason as well.

Motion equations describing movement in accelerating frames
formally include the fictitious forces, to keep formula
vec F = m . vec a
valid even for accelerating frames.

To keep a body not accelerating in accelerating frame,
the same force as the fictitious one but the opposite
has act upon the body.

For the rotating accelerating frames like the natural Earth frame,
there are 3 fictitious forces.

Centrifugal force, related to the body position.
Coriolis force, related to the body velocity.( the most known )
Euler force, related to acceleration of rotation, negligible for Earth.


-- 
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

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